The present invention relates to the preparation of co-salts of polyunsaturated fatty acids (PUFA) and another anion such as citrate, phosphate, lactate, fumarate, gluconate, carbonate, bicarbonate, malate, or other anions of common acids and the co-precipitated salts of the fatty acid and the anion. The present invention particularly relates to mixtures of monovalent and divalent metal salts rich in omega-3 and omega-6 fatty acids including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), eicosatetraenoic acid (ETA), heneicosatetraenoic acid (HPA), linoleic acid (LA), alpha linolenic acid (ALA) and arachidonic acid (ARA), in general known as omega-3 or -6 fatty acids.
Several salts, such as calcium, magnesium, copper, zinc, iron, manganese, potassium, ammonium, sodium, and several others have long been recognized as beneficial mineral nutrients for humans and certain companion animals and livestock, such as dogs, cats, cattle, horses, goats, pigs, birds, fish and others. Calcium is known to be essential for the maintaining of bones and teeth. It is also responsible for a normal heartbeat and helps regulate blood pressure. The divalent cation magnesium acts as a calcium antagonist at the cell membrane level which is necessary to maintain normal electrical potentials and to coordinate muscle contraction-relaxation responses. Additionally, magnesium has roles in energy metabolism as a required cofactor for enzymes that catalyze fatty acid synthesis, protein synthesis, and glucose metabolism. Copper is utilized as an enzyme for many biochemical reactions within the biological system of birds and mammals. Copper deficiency is known to cause anemia, bone disorders, neonatal ataxia, cardiovascular disorders, and many other maladies due to the inability of certain enzymes functioning properly.
Zinc also is essential for protein synthesis, integrity of cell membranes, maintenance of DNA and RNA, tissue growth and repair, wound healing, taste acuity, prostaglandin production, bone mineralization, proper thyroid function, blood clotting and cognitive functions.
A variety of omega-3 fatty acids have been identified as desirable for producing a diversity of nutritional and physiological benefits in humans and lower animals and accordingly have found value as nutritional supplements for a wide variety of animals. In certain animals, omega-3 fatty acids, for example, have been discovered to promote fertility, promote healthy skin and coat, reduce inflammation, and have other nutritional and physiological properties as well. In humans, it is believed that omega-3 fatty acids such as EPA and DHA support healthy cardiovascular function and are important for visual and neuronal development, support healthy blood levels of cholesterol, triglycerides and very low density lipoproteins, ease the inflammation associated with overuse of joints, and improve carbohydrate metabolism. The FDA allows the following claim to be added to products that contain omega-3:                “Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease.”        
In developing fetuses and children, omega-3 fatty acids have been shown to be necessary for the eyes, brain, and developing central nervous system. In adults, omega-3 fatty acids have been shown to maintain normal cardiovascular function and maintain healthy brain and immune system function.
It has also been shown that supplementing the diet of livestock with omega-3 fatty acids will alter the livestock fatty acid profile, so that, for example, feeding dairy cows and beef cattle a source of these unsaturated fatty acids will yield dairy and beef products for human consumption enriched with the beneficial polyunsaturated fatty acids (PUFA).